diff options
Diffstat (limited to 'arch/sh/drivers/pci/ops-cayman.c')
-rw-r--r-- | arch/sh/drivers/pci/ops-cayman.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/ops-cayman.c b/arch/sh/drivers/pci/ops-cayman.c new file mode 100644 index 000000000000..980275ffa30b --- /dev/null +++ b/arch/sh/drivers/pci/ops-cayman.c @@ -0,0 +1,94 @@ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/types.h> +#include <asm/cpu/irq.h> +#include "pci-sh5.h" + +static inline u8 bridge_swizzle(u8 pin, u8 slot) +{ + return (((pin - 1) + slot) % 4) + 1; +} + +int __init pcibios_map_platform_irq(struct pci_dev *dev, u8 slot, u8 pin) +{ + int result = -1; + + /* The complication here is that the PCI IRQ lines from the Cayman's 2 + 5V slots get into the CPU via a different path from the IRQ lines + from the 3 3.3V slots. Thus, we have to detect whether the card's + interrupts go via the 5V or 3.3V path, i.e. the 'bridge swizzling' + at the point where we cross from 5V to 3.3V is not the normal case. + + The added complication is that we don't know that the 5V slots are + always bus 2, because a card containing a PCI-PCI bridge may be + plugged into a 3.3V slot, and this changes the bus numbering. + + Also, the Cayman has an intermediate PCI bus that goes a custom + expansion board header (and to the secondary bridge). This bus has + never been used in practice. + + The 1ary onboard PCI-PCI bridge is device 3 on bus 0 + The 2ary onboard PCI-PCI bridge is device 0 on the 2ary bus of + the 1ary bridge. + */ + + struct slot_pin { + int slot; + int pin; + } path[4]; + int i=0; + + while (dev->bus->number > 0) { + + slot = path[i].slot = PCI_SLOT(dev->devfn); + pin = path[i].pin = bridge_swizzle(pin, slot); + dev = dev->bus->self; + i++; + if (i > 3) panic("PCI path to root bus too long!\n"); + } + + slot = PCI_SLOT(dev->devfn); + /* This is the slot on bus 0 through which the device is eventually + reachable. */ + + /* Now work back up. */ + if ((slot < 3) || (i == 0)) { + /* Bus 0 (incl. PCI-PCI bridge itself) : perform the final + swizzle now. */ + result = IRQ_INTA + bridge_swizzle(pin, slot) - 1; + } else { + i--; + slot = path[i].slot; + pin = path[i].pin; + if (slot > 0) { + panic("PCI expansion bus device found - not handled!\n"); + } else { + if (i > 0) { + /* 5V slots */ + i--; + slot = path[i].slot; + pin = path[i].pin; + /* 'pin' was swizzled earlier wrt slot, don't do it again. */ + result = IRQ_P2INTA + (pin - 1); + } else { + /* IRQ for 2ary PCI-PCI bridge : unused */ + result = -1; + } + } + } + + return result; +} + +struct pci_channel board_pci_channels[] = { + { &sh5_pci_ops, NULL, NULL, 0, 0xff }, + { NULL, NULL, NULL, 0, 0 }, +}; +EXPORT_SYMBOL(board_pci_channels); + +int __init pcibios_init_platform(void) +{ + return sh5pci_init(__pa(memory_start), + __pa(memory_end) - __pa(memory_start)); +} |